Coordinate Systems. Basis for any 3D Coordinate System. 2. Locate the x-y plane (the fundamental plane ) Usual approach to define angles:

Size: px
Start display at page:

Download "Coordinate Systems. Basis for any 3D Coordinate System. 2. Locate the x-y plane (the fundamental plane ) Usual approach to define angles:"

Transcription

1 Coordinate Systems Basis for any 3D Coordinate System Basic steps for the definition of a 3D coordinate system:. Locate the origin. Locate the -y plane (the fundamental plane ) 3. Decide on direction of positive ais ( reference direction ) 4. Decide on sign convention of y and z aes Usual approach to define angles: First angle from + to +y ais [0 α,φ,λ π] Second angle from -y plane to +z ais [-π/ θ,δ,ξ +π/] or [0 θ,δ,ξ π]

2 Earth rotation, ais-tilt, orbit,... source: Wikipedia The rotation ais of the Earth is tilted by about 3.44 (3 6 ) relative to the orbital plane. Definitions (): the Meridian A meridian is a great circle on the celestial sphere passing through: the north point on the horizon H the celestial pole P the zenith Z the south point on the horizon H sou urce: Wikipedia The meridian is perpendicular to the local horizon. Stars will appear to drift past the local meridian as the Earth spins.

3 Definitions (): Equino Equino derives from `aequus (equal) and `no (night). Equino when the centre of the Sun can be observed to be directly above the Earth s equator (i.e., declination δ0). At an equino, the Sun will spend equal time above and below the horizon at every location on Earth. Intersection point between celestial equator (δ0) and ecliptic: vernal/autumnal equino. source: Wikip pedia Def. (3): Hour Angle and ight Ascension The hour angle is the angle between the meridian plane and the half plane determined by the Earth's ais and the given point. The hour angle is epressed in time units, with one hour 360 /4hr 5. The right ascension α is the angle VOQ between the vernal equino and the given point on the equator. The hour angle is also the difference between local siderial time (LST) and right ascension α: The object's hour angle indicates how much sidereal time has passed since the object was on the local meridian.

4 I. The Horizontal Frame (Alt-Azimuth) Origin: Position of the observer Aes: local vertical (gravity vector) horizon Coordinates: azimuth A from South height h U ( A, h) 3 cos Acos h sin Acos h sin h Problem: apparent motion of the celestial sphere. Note: due to tidal forces the gravity vector changes and hence the coordinates relative to surface structures by typically 0.05ʺ II. The Hour Frame (Latitute-Longitude) Choose celestial equator as fundamental plane. Origin: Position of the observer Aes: vector to celestial pole vector to celestial equator (rot) Coordinates: declination δ (latitude) hour angle H U ( H, δ ) cos H cosδ sin H cosδ sinδ 3 Problem: refers to the observer s local meridian.

5 III. The Equatorial Frame emoves the largest component of Earth rotation. Aes: vector to celestial pole vector to celestial equator (fied) Coordinates: declination δ (latitude) right ascension α (A) cosα cosδ U ( α, δ ) sin α cos δ sinδ 3 The equatorial frame is used for most star and galay catalogues.

6 IV. The Ecliptic Frame Best for charting solar system objects Aes: normal to the orbital plane vector to vernal equino Coordinates: ecliptic lattitudeβ ecliptic longitude λ Problem: orbital plane (Earth-Sun vector) is sensitive to perturbations by the other planets oscillations of ~ʺ about mean plane. V. The Galactic Frame Useful to chart stellar populations in the MilkyWay. Origin: Sun Aes: rotation vector of the Galay vector to the Galactic Center Coordinates: galactic latitude b galactic longitude l source: Wikipedia Definition: North Galactic pole at h 5 m 6.8 s +7 07' 4.0" (J000) zero longitude at position angle.93 zero point is at 7 h 45 m 37.4 s 8 56' 0.3" (J000), close to Sgr A*

7 VI. The Supergalactic Frame Equator aligned with the supergalactic plane formed by the nearby galay clusters Virgo, the Great Attractor and the Pisces-Perseus supercluster. Coordinates: supergalactic lattitude SGB supergalactic longitude SGL Zero point for SGL is the intersection of the supergalactic plane with the Galactic plane The nearest 0 Mpc in SG coordinates Definition: North supergalactic pole at l 47.37, b+6.3 or A8.9 h, δ+5.7 (J000). Zero point (SGB0, SGL0 ) at l37.37, b0 or A.8 h, δ+59.5 (J000). Coordinate Frame Transformations ' The hard way: [ ] ' ' cos β 0 sin β cos γ sin γ 0 α 0 cosα sinα β 0 0 ( ) 3 γ sin γ cosγ 0 0 sinα cosα sin β 0 cos β 0 0 ( ) ( ). Calculate Cartesian coordinates [,, 3 ]. Apply rotation 3. Calculate transformed frame coordinates see Monday eercises

8 Eample: from Equatorial to Galactic Frame ( ) ( ) ( ) ( ) ( ) δ α ψ θ φ β λ,, U U ( ) ( ) ( ) ( ) ( ) δ α ψ θ φ β λ,, 3 3 U U 3 ' 3 ' ' See book by Lena for details Coordinate Frame Transformations () The easy way:

9 Paralla and Orbital Motion Paralla semi-angle of inclination between two sightlines to a star. Precession and Nutation Precession movement of the direction of the Earth s rotational ais, caused mainly by Sun and Moon. period: 5,764 years magnitude: ~50ʺ source: Wikipedia Nutation tidal forces of Sun and Moon are continuously changing with their relative positions cause precession to vary over time. period: 8.6 years (largest component) magnitude: ~9.ʺ

10 Position of the Sun the Analemma O circular orbit, no aial tilt: analemma is a dot circular orbit and aial tilt: analemma is a figure of eight; N and S lobes equal eccentric orbit, no aial tilt: analemma is a straight E-W line along the equator Photomontage illustrating an analemma pattern in the sky. Were one to take a photo of the sun each week for a year and combine the images taken, this pattern would be visible (from Wikipedia). SO Ephemeris Time (ET) The ephemeris time was defined by Simon Newcomb s (898) tables* of the Earth s orbital motion around the Sun, later (more practically) by the orbital motion of the Moon around the Earth. Definition: One second (defined in 900) /3,556, of the tropical year for 900 January 0 at hours ephemeris time. (since 967 one uses atomic standards) One Julian day has 86,400 seconds One Julian century has 36,55 days One tropical year has days *an ephemeris is a table of values that gives the positions of astronomical objects in the sky at a given time

11 Universal Time (UT) Timescale based on the rotation of the Earth. eference location is Greenwich meridian : UT hours + Greenwich hour angle Ideally, noon Greenwich Mean Time is when the Sun crosses the Greenwich meridian. But: variations in the Earth's orbit (nutation, ellipticity, aial tilt) cause differences of up to 6 minutes. Use Newcomb s fictitious mean Sun hence also called Greenwich mean time G.M.T. ) Nowadays, use atomic standards won t slow down but require occasional one second discontinuities to keep the Earth rotation in phase with atomic clocks UTC (coordinated universal time). Sidereal Time (ST) Sidereal time hour angle of the true vernal equino The sidereal time is proportional to the UTC. It has the same value as the right ascension of any celestial body that is crossing the local meridian at that same moment. When one moves eastward 5 in longitude, the sidereal time increases by one hour. Note: when ST A the object will be at culmination. When corrected for nutation mean sidereal time. Eample: Local sidereal time (LST) at Leiden: 5 09'N 04 30'E: Use, e.g. to check

12 Sidereal Day Every 4.00 hr the Sun reaches the highest position in the South ( synodic day) In the meantime, the Earth has rotated a bit more than 360 degrees as it orbits the Sun, (namely 360 / ). source: Wikipedia Thus, a sidereal day is shorter: 4hr 360 / hr 56min

Geometry of Earth Sun System

Geometry of Earth Sun System 12S56 Geometry of Earth Sun System Figure below shows the basic geometry Northern Hemisphere Winter ω equator Earth s Orbit Ecliptic ω ω SUN equator Northern Hemisphere Spring Northern Hemisphere Fall

More information

Modern Navigation. Thomas Herring

Modern Navigation. Thomas Herring 12.215 Modern Navigation Thomas Herring Review of Monday s Class Spherical Trigonometry Review plane trigonometry Concepts in Spherical Trigonometry Distance measures Azimuths and bearings Basic formulas:

More information

Chapter S1 Celestial Timekeeping and Navigation. How do we define the day, month, year, and planetary time periods?

Chapter S1 Celestial Timekeeping and Navigation. How do we define the day, month, year, and planetary time periods? Chapter S1 Celestial Timekeeping and Navigation S1.1 Astronomical Time Periods Our goals for learning:! How do we define the day, month, year, and planetary time periods?! How do we tell the time of day?!

More information

LOCATING CELESTIAL OBJECTS: COORDINATES AND TIME. a. understand the basic concepts needed for any astronomical coordinate system.

LOCATING CELESTIAL OBJECTS: COORDINATES AND TIME. a. understand the basic concepts needed for any astronomical coordinate system. UNIT 2 UNIT 2 LOCATING CELESTIAL OBJECTS: COORDINATES AND TIME Goals After mastery of this unit, you should: a. understand the basic concepts needed for any astronomical coordinate system. b. understand

More information

Chapter S1 Lecture. The Cosmic Perspective Seventh Edition. Celestial Timekeeping and Navigation Pearson Education, Inc.

Chapter S1 Lecture. The Cosmic Perspective Seventh Edition. Celestial Timekeeping and Navigation Pearson Education, Inc. Chapter S1 Lecture The Cosmic Perspective Seventh Edition Celestial Timekeeping and Navigation 2014 Pearson Education, Inc. Celestial Timekeeping and Navigation 2014 Pearson Education, Inc. S1.1 Astronomical

More information

Knowing the Heavens. Goals: Constellations in the Sky

Knowing the Heavens. Goals: Constellations in the Sky Goals: Knowing the Heavens To see how the sky changes during a night and from night to night. To measure the positions of stars in celestial coordinates. To understand the cause of the seasons. Constellations

More information

Knowing the Heavens. Goals: Constellations in the Sky

Knowing the Heavens. Goals: Constellations in the Sky Goals: Knowing the Heavens To see how the sky changes during a night and from night to night. To measure the positions of stars in celestial coordinates. To understand the cause of the seasons. Constellations

More information

Appearance of the Sky Orientation Motion of sky Seasons Precession (?)

Appearance of the Sky Orientation Motion of sky Seasons Precession (?) Today Appearance of the Sky Orientation Motion of sky Seasons Precession (?) The Celestial Sphere Stars at different distances all appear to lie on the celestial sphere. The ecliptic is the Sun s apparent

More information

PHAS 1511: Foundations of Astronomy

PHAS 1511: Foundations of Astronomy PHAS 1511: Foundations of Astronomy Dr Roger Wesson Research interests: deaths of stars. Planetary nebulae, novae and supernovae. Astronomy: some maths You can see that distances in astronomy are huge.

More information

Appearance of the Sky Orientation Motion of sky Seasons Precession (?)

Appearance of the Sky Orientation Motion of sky Seasons Precession (?) Today Appearance of the Sky Orientation Motion of sky Seasons Precession (?) The Celestial Sphere Stars at different distances all appear to lie on the celestial sphere. The ecliptic is the Sun s apparent

More information

Topic Guide: The Celestial Sphere. GCSE (9-1) Astronomy. Pearson Edexcel Level 1/Level 2 GCSE (9-1) in Astronomy (1AS0)

Topic Guide: The Celestial Sphere. GCSE (9-1) Astronomy. Pearson Edexcel Level 1/Level 2 GCSE (9-1) in Astronomy (1AS0) Topic Guide: The Celestial Sphere GCSE (9-1) Astronomy Pearson Edexcel Level 1/Level 2 GCSE (9-1) in Astronomy (1AS0) The Celestial Sphere Contents Specification Points 1 The Astronomy 2 Equatorial coordinates

More information

Astronomy 291. Professor Bradley M. Peterson

Astronomy 291. Professor Bradley M. Peterson Astronomy 291 Professor Bradley M. Peterson The Sky As a first step, we need to understand the appearance of the sky. Important points (to be explained): The relative positions of stars remain the same

More information

Astronomical coordinate systems. ASTR320 Monday January 22, 2018

Astronomical coordinate systems. ASTR320 Monday January 22, 2018 Astronomical coordinate systems ASTR320 Monday January 22, 2018 Special public talk this week: Mike Brown, Pluto Killer Wednesday at 7:30pm in MPHY204 Other news Munnerlyn lab is hiring student engineers

More information

These notes may contain copyrighted material! They are for your own use only during this course.

These notes may contain copyrighted material! They are for your own use only during this course. Licensed for Personal Use Only DO NOT DISTRIBUTE These notes may contain copyrighted material! They are for your own use only during this course. Distributing them in anyway will be considered a breach

More information

Introduction To Modern Astronomy I: Solar System

Introduction To Modern Astronomy I: Solar System ASTR 111 003 Fall 2007 Lecture 02 Sep. 10, 2007 Introduction To Modern Astronomy I: Solar System Introducing Astronomy (chap. 1-6) Planets and Moons (chap. 7-15) Chap. 16: Our Sun Chap. 28: Search for

More information

The sky and the celestial sphere

The sky and the celestial sphere Chapter 1 The sky and the celestial sphere The Sun, and sometimes the Moon are, by and large, the only astronomical objects visible in the day sky. Traditionally, astronomy has been a nocturnal activity.

More information

is a revolution relative to a fixed celestial position. is the instant of transit of mean equinox relative to a fixed meridian position.

is a revolution relative to a fixed celestial position. is the instant of transit of mean equinox relative to a fixed meridian position. PERIODICITY FORMULAS: Sidereal Orbit Tropical Year Eclipse Year Anomalistic Year Sidereal Lunar Orbit Lunar Mean Daily Sidereal Motion Lunar Synodical Period Centenial General Precession Longitude (365.25636042

More information

Chapter 1: Discovering the Night Sky. The sky is divided into 88 unequal areas that we call constellations.

Chapter 1: Discovering the Night Sky. The sky is divided into 88 unequal areas that we call constellations. Chapter 1: Discovering the Night Sky Constellations: Recognizable patterns of the brighter stars that have been derived from ancient legends. Different cultures have associated the patterns with their

More information

Fundamentals of Satellite technology

Fundamentals of Satellite technology Fundamentals of Satellite technology Prepared by A.Kaviyarasu Assistant Professor Department of Aerospace Engineering Madras Institute Of Technology Chromepet, Chennai Orbital Plane All of the planets,

More information

Astronomy. The Seasons

Astronomy. The Seasons Astronomy The Seasons The seasons are caused by the inclination of the Earth s axis: when a hemisphere is tipped toward the Sun, the Sun is more directly above it. At the Summer Solstice the tilt is most

More information

Understanding Positional Astronomy Part 2 Celestial Co-ordinates Difficulty: Intermediate

Understanding Positional Astronomy Part 2 Celestial Co-ordinates Difficulty: Intermediate Exercise: Understanding Positional Astronomy Part 2 Celestial Co-ordinates Difficulty: Intermediate Objectives In Part 1 you learned about Celestial Sphere and how the stars appear to move across the night

More information

2. Modern: A constellation is a region in the sky. Every object in the sky, whether we can see it or not, is part of a constellation.

2. Modern: A constellation is a region in the sky. Every object in the sky, whether we can see it or not, is part of a constellation. 6/14 10. Star Cluster size about 10 14 to 10 17 m importance: where stars are born composed of stars. 11. Galaxy size about 10 21 m importance: provide a stable environment for stars. Composed of stars.

More information

Ay 1 Lecture 2. Starting the Exploration

Ay 1 Lecture 2. Starting the Exploration Ay 1 Lecture 2 Starting the Exploration 2.1 Distances and Scales Some Commonly Used Units Distance: Astronomical unit: the distance from the Earth to the Sun, 1 au = 1.496 10 13 cm ~ 1.5 10 13 cm Light

More information

Essential Astrophysics

Essential Astrophysics ASTR 530 Essential Astrophysics Course Notes Paul Hickson The University of British Columbia, Department of Physics and Astronomy January 2015 1 1 Introduction and review Several text books present an

More information

6/17. Universe from Smallest to Largest:

6/17. Universe from Smallest to Largest: 6/17 Universe from Smallest to Largest: 1. Quarks and Leptons fundamental building blocks of the universe size about 0 (?) importance: quarks combine together to form neutrons and protons. One of the leptons

More information

Discovering the Night Sky

Discovering the Night Sky Discovering the Night Sky Guiding Questions 1. What role did astronomy play in ancient civilizations? 2. Are the stars that make up a constellation actually close to one another? 3. Are the same stars

More information

Discovering the Night Sky

Discovering the Night Sky Guiding Questions Discovering the Night Sky 1. What role did astronomy play in ancient civilizations? 2. Are the stars that make up a constellation actually close to one another? 3. Are the same stars

More information

Knowing the Heavens. Chapter Two. Guiding Questions. Naked-eye (unaided-eye) astronomy had an important place in ancient civilizations

Knowing the Heavens. Chapter Two. Guiding Questions. Naked-eye (unaided-eye) astronomy had an important place in ancient civilizations Knowing the Heavens Chapter Two Guiding Questions 1. What role did astronomy play in ancient civilizations? 2. Are the stars that make up a constellation actually close to one another? 3. Are the same

More information

Aileen A. O Donoghue Priest Associate Professor of Physics

Aileen A. O Donoghue Priest Associate Professor of Physics SOAR: The Sky in Motion Life on the Tilted Teacup Ride The Year Aileen A. O Donoghue Priest Associate Professor of Physics Celestial Coordinates Right Ascension RA or From prime meridian (0 h ) to 23 h

More information

Coordinate Systems for Astronomy or: How to get your telescope to observe the right object

Coordinate Systems for Astronomy or: How to get your telescope to observe the right object Coordinate Systems for Astronomy or: How to get your telescope to observe the right object Figure 1: Basic definitions for the Earth Definitions - Poles, Equator, Meridians, Parallels The rotation of the

More information

Summary Sheet #1 for Astronomy Main Lesson

Summary Sheet #1 for Astronomy Main Lesson Summary Sheet #1 for Astronomy Main Lesson From our perspective on earth The earth appears flat. We can see half the celestial sphere at any time. The earth s axis is always perpendicular to the equator.

More information

The Measurement of Time

The Measurement of Time CHAPTER TWO The Measurement of Time Solar Time In antiquity the time of day was measured by the direction of a shadow cast in sunlight. This resulted in the development of a wide variety of sophisticated

More information

HNRS 227 Fall 2007 Chapter 14. Earth in Space presented by Prof. Geller 25 October 2007

HNRS 227 Fall 2007 Chapter 14. Earth in Space presented by Prof. Geller 25 October 2007 HNRS 227 Fall 2007 Chapter 14 Earth in Space presented by Prof. Geller 25 October 2007 Key Points of Chapter 14 Shape, Size and Motions of the Earth Rotation and Revolution Precession Coordinate Systems

More information

The Position of the Sun. Berthold K. P. Horn. necessary to know the position of the sun in the sky. This is particularly

The Position of the Sun. Berthold K. P. Horn. necessary to know the position of the sun in the sky. This is particularly MASSACHUSETTS INSTITUTE OF TECHNOLOGY ARTIFICIAL INTELLIGENCE LABORATORY Working Paper No. 162 March 1978 The Position of the Sun Berthold K. P. Horn Abstract. The appearance of a surface depends dramatically

More information

Equatorial Telescope Mounting

Equatorial Telescope Mounting Equatorial Telescope Mounting Star Catalogs simbad IRSA The Meridian Every line of celestial longitude is a meridian of longitude, but we recognize the line of longitude, or simply the great circle line,

More information

A Warm Up Exercise. The Motion of the Sun. A Warm Up Exercise. A Warm Up Exercise. A Warm Up Exercise

A Warm Up Exercise. The Motion of the Sun. A Warm Up Exercise. A Warm Up Exercise. A Warm Up Exercise A Warm Up Exercise The Motion of the Sun Which of the following is NOT true of a circumpolar star? a) It rises and sets from my latitude b) Its direction can be far North c) Its direction can be far South

More information

ASTRONOMICAL COORDINATE SYSTEMS CELESTIAL SPHERE

ASTRONOMICAL COORDINATE SYSTEMS CELESTIAL SPHERE ASTRONOMICAL COORDINATE SYSTEMS CELESTIAL SPHERE To the naked eye, stars appear fixed on the sky with respect to one another. These patterns are often grouped into constellations. Angular measurements

More information

Observing the Universe for Yourself

Observing the Universe for Yourself Observing the Universe for Yourself Figure 6-20 Solar-System Formation What does the universe look like from Earth? With the naked eye, we can see more than 2,000 stars as well as the Milky Way. A constellation

More information

Lunar Eclipse Wednesday (January 31 st ) Morning. Topics for Today s Class. PHYS 1403 Stars and Galaxies

Lunar Eclipse Wednesday (January 31 st ) Morning. Topics for Today s Class. PHYS 1403 Stars and Galaxies PHYS 1403 Stars and Galaxies Lunar Eclipse Wednesday (January 31 st ) Morning Super Moon so visible with naked eye Look in the western horizon Penumbral eclipse starts at 5:00 am Totality begins at 7:00

More information

Chapter 0 2/19/2014. Lecture Outline. 0.1 The Obvious View. Charting the Heavens. 0.1 The Obvious View. 0.1 The Obvious View. Units of Chapter 0

Chapter 0 2/19/2014. Lecture Outline. 0.1 The Obvious View. Charting the Heavens. 0.1 The Obvious View. 0.1 The Obvious View. Units of Chapter 0 Lecture Outline Chapter 0 Charting the Heavens Earth is average we don t occupy any special place in the universe Universe: Totality of all space, time, matter, and energy Astronomy: Study of the universe

More information

PHSC 1053: Astronomy Time and Coordinates

PHSC 1053: Astronomy Time and Coordinates PHSC 1053: Astronomy Time and Coordinates Astronomical Clocks Earth s Rotation on its Axis Time between two successive meridian transits of the sun 1 solar day (our adopted clock time) 24 hours (86,400

More information

Meridian Circle through Zenith, North Celestial Pole, Zenith Direction Straight Up from Observer. South Celestial Pole

Meridian Circle through Zenith, North Celestial Pole, Zenith Direction Straight Up from Observer. South Celestial Pole Chapter 3 How Earth and Sky Work- Effects of Latitude In chapters 3 and 4we will learn why our view of the heavens depends on our position on the Earth, the time of day, and the day of the year. We will

More information

Earth Science, 13e Tarbuck & Lutgens

Earth Science, 13e Tarbuck & Lutgens Earth Science, 13e Tarbuck & Lutgens Origins of Modern Astronomy Earth Science, 13e Chapter 21 Stanley C. Hatfield Southwestern Illinois College Early history of astronomy Ancient Greeks Used philosophical

More information

10/17/2012. Observing the Sky. Lecture 8. Chapter 2 Opener

10/17/2012. Observing the Sky. Lecture 8. Chapter 2 Opener Observing the Sky Lecture 8 Chapter 2 Opener 1 Figure 2.1 Figure 2.2 2 Figure 2.6 Figure 2.4 Annotated 3 The Celestial Sphere The celestial sphere is the vast hollow sphere on which the stars appear fixed.

More information

2. Descriptive Astronomy ( Astronomy Without a Telescope )

2. Descriptive Astronomy ( Astronomy Without a Telescope ) How do we locate stars in the heavens? 2. Descriptive Astronomy ( Astronomy Without a Telescope ) What stars are visible from a given location? Where is the sun in the sky at any given time? Where are

More information

The celestial sphere, the coordinates system, seasons, phases of the moon and eclipses. Chapters 2 and S1

The celestial sphere, the coordinates system, seasons, phases of the moon and eclipses. Chapters 2 and S1 The celestial sphere, the coordinates system, seasons, phases of the moon and eclipses Chapters 2 and S1 The celestial sphere and the coordinates system Chapter S1 How to find our way in the sky? Let s

More information

Observational Astronomy - Lecture 5 The Motion of the Earth and Moon Time, Precession, Eclipses, Tides

Observational Astronomy - Lecture 5 The Motion of the Earth and Moon Time, Precession, Eclipses, Tides Observational Astronomy - Lecture 5 The Motion of the Earth and Moon Time, Precession, Eclipses, Tides Craig Lage New York University - Department of Physics craig.lage@nyu.edu March 2, 2014 1 / 29 Geosynchronous

More information

Physics 312 Introduction to Astrophysics Lecture 3

Physics 312 Introduction to Astrophysics Lecture 3 Physics 312 Introduction to Astrophysics Lecture 3 James Buckley buckley@wuphys.wustl.edu Lecture 3 Celestial Coordinates the Planets and more History Reason for the Seasons Summer Solstice: Northern Hemisphere

More information

CELESTIAL COORDINATES

CELESTIAL COORDINATES ASTR 1030 Astronomy Lab 27 Celestial Coordinates CELESTIAL COORDINATES GEOGRAPHIC COORDINATES The Earth's geographic coordinate system is familiar to everyone - the north and south poles are defined by

More information

UNIT 6 CELESTIAL SPHERE AND EQUINOCTIAL SYSTEM OF COORDINATES

UNIT 6 CELESTIAL SPHERE AND EQUINOCTIAL SYSTEM OF COORDINATES UNIT 6 CELESTIAL SPHERE AND EQUINOCTIAL SYSTEM OF COORDINATES Structure 6.1 Introduction Objectives 6.2 References 6.3 Apparent Annual Motion of the Sun and the Concept of the Ecliptic and the Obliquity

More information

RECOMMENDATION ITU-R S Impact of interference from the Sun into a geostationary-satellite orbit fixed-satellite service link

RECOMMENDATION ITU-R S Impact of interference from the Sun into a geostationary-satellite orbit fixed-satellite service link Rec. ITU-R S.1525-1 1 RECOMMENDATION ITU-R S.1525-1 Impact of interference from the Sun into a geostationary-satellite orbit fixed-satellite service link (Question ITU-R 236/4) (21-22) The ITU Radiocommunication

More information

Oberth: Energy vs. Momentum

Oberth: Energy vs. Momentum 1 2 The Oberth Effect 3 Oberth: Energy vs. Momentum 4 The Celestial Sphere From our perspective on Earth the stars appear embedded on a distant 2-dimensional surface the Celestial Sphere. 5 The Celestial

More information

Name: Date: 5. The bright stars Vega, Deneb, and Altair form A) the summer triangle. B) the winter triangle. C) the Big Dipper. D) Orion, the Hunter.

Name: Date: 5. The bright stars Vega, Deneb, and Altair form A) the summer triangle. B) the winter triangle. C) the Big Dipper. D) Orion, the Hunter. Name: Date: 1. If there are about 6000 stars in the entire sky that can be seen by the unaided human eye, about how many stars would be seen at a particular instant on a given dark night from a single

More information

Celestial Mechanics III. Time and reference frames Orbital elements Calculation of ephemerides Orbit determination

Celestial Mechanics III. Time and reference frames Orbital elements Calculation of ephemerides Orbit determination Celestial Mechanics III Time and reference frames Orbital elements Calculation of ephemerides Orbit determination Orbital position versus time: The choice of units Gravitational constant: SI units ([m],[kg],[s])

More information

Earth s Orbit. Sun Earth Relationships Ridha Hamidi, Ph.D. ESCI-61 Introduction to Photovoltaic Technology

Earth s Orbit. Sun Earth Relationships Ridha Hamidi, Ph.D. ESCI-61 Introduction to Photovoltaic Technology 1 ESCI-61 Introduction to Photovoltaic Technology Sun Earth Relationships Ridha Hamidi, Ph.D. Spring (sun aims directly at equator) Winter (northern hemisphere 23.5 tilts away from sun) 2 Solar radiation

More information

Chapter 2 Discovering the Universe for Yourself. Copyright 2012 Pearson Education, Inc.

Chapter 2 Discovering the Universe for Yourself. Copyright 2012 Pearson Education, Inc. Chapter 2 Discovering the Universe for Yourself 1 2.1 Patterns in the Night Sky Our goals for learning: What does the universe look like from Earth? Why do stars rise and set? Why do the constellations

More information

Sundials and the Celestial Sphere. Katie Hausknecht

Sundials and the Celestial Sphere. Katie Hausknecht Sundials and the Celestial Sphere Katie Hausknecht What is a sundial? A sundial is a device that uses the shadow cast by the sun to indicate what time of day it is, often by hours. The Celestial Sphere

More information

Welcome to Astronomy 402/602

Welcome to Astronomy 402/602 Welcome to Astronomy 402/602 Introductions Syllabus Telescope proposal Coordinate Systems (Lecture) Coordinate System Exercise Light (Lecture) Telescopes (Lecture) Syllabus Course goals Course expectations

More information

A Sky Full of Stars - II.

A Sky Full of Stars - II. A Sky Full of Stars - II. Learning Objectives! What is the latitude of the Equator and of the Earth s North and South Poles? What is the declination of the Celestial Equator and of the Celestial Poles?!

More information

Introduction to Astronomy

Introduction to Astronomy Introduction to Astronomy AST0111-3 (Astronomía) Semester 2014B Prof. Thomas H. Puzia Theme Our Sky 1. Celestial Sphere 2. Diurnal Movement 3. Annual Movement 4. Lunar Movement 5. The Seasons 6. Eclipses

More information

PHYS 160 Astronomy Test #1 Fall 2017 Version B

PHYS 160 Astronomy Test #1 Fall 2017 Version B PHYS 160 Astronomy Test #1 Fall 2017 Version B 1 I. True/False (1 point each) Circle the T if the statement is true, or F if the statement is false on your answer sheet. 1. An object has the same weight,

More information

Equator SOME NOTES ON THE EQUATION OF TIME. λ α. Ecliptic. by Carlos Herrero

Equator SOME NOTES ON THE EQUATION OF TIME. λ α. Ecliptic. by Carlos Herrero SOME NOTES ON THE EQUATION OF TIME by Carlos Herrero Version v2.1, February 214 I. INTRODUCTION Since ancient times humans have taken the Sun as a reference for measuring time. This seems to be a natural

More information

Dynamics of the Earth

Dynamics of the Earth Time Dynamics of the Earth Historically, a day is a time interval between successive upper transits of a given celestial reference point. upper transit the passage of a body across the celestial meridian

More information

A2 Principi di Astrofisica. Coordinate Celesti

A2 Principi di Astrofisica. Coordinate Celesti A2 Principi di Astrofisica Coordinate Celesti ESO La Silla Tel. 3.6m Celestial Sphere Our lack of depth perception when we look into space creates the illusion that Earth is surrounded by a celestial sphere.

More information

Celestial Sphere Spectroscopy (Something interesting; e.g., advanced data analyses with IDL)

Celestial Sphere Spectroscopy (Something interesting; e.g., advanced data analyses with IDL) AST326, 2010 Winter Semester Celestial Sphere Spectroscopy (Something interesting; e.g., advanced data analyses with IDL) Practical Assignment: analyses of Keck spectroscopic data from the instructor (can

More information

The Earth, Moon, and Sky. Lecture 5 1/31/2017

The Earth, Moon, and Sky. Lecture 5 1/31/2017 The Earth, Moon, and Sky Lecture 5 1/31/2017 From Last Time: Stable Orbits The type of orbit depends on the initial speed of the object Stable orbits are either circular or elliptical. Too slow and gravity

More information

Question 1. What motion is responsible for the apparent motion of the constellations (east to west) across the sky?

Question 1. What motion is responsible for the apparent motion of the constellations (east to west) across the sky? What motion is responsible for the apparent motion of the constellations (east to west) across the sky? Question 1 1) the motion of Earth around the Sun 2) the motion of the Moon around Earth 3) the motion

More information

Observing the Night Sky: Locating Objects

Observing the Night Sky: Locating Objects Observing the Night Sky: Locating Objects As I left the house this morning, there was a bright bluish light above and to the left of my neighbors house (approximately East) and a big very bright object

More information

4 Solar System and Time

4 Solar System and Time 4 olar ystem and Time 4.1 The Universe 4.1.1 Introduction The Universe consists of countless galaxies distributed throughout space. The bodies used in astro navigation belong to the Galaxy known as the

More information

Earth Science, 11e. Origin of Modern Astronomy Chapter 21. Early history of astronomy. Early history of astronomy. Early history of astronomy

Earth Science, 11e. Origin of Modern Astronomy Chapter 21. Early history of astronomy. Early history of astronomy. Early history of astronomy 2006 Pearson Prentice Hall Lecture Outlines PowerPoint Chapter 21 Earth Science 11e Tarbuck/Lutgens This work is protected by United States copyright laws and is provided solely for the use of instructors

More information

2. Descriptive Astronomy ( Astronomy Without a Telescope )

2. Descriptive Astronomy ( Astronomy Without a Telescope ) 2. Descriptive Astronomy ( Astronomy Without a Telescope ) http://apod.nasa.gov/apod/astropix.html How do we locate stars in the heavens? What stars are visible from a given location? Where is the sun

More information

Local Coordinates. These are centered upon you, the observer.

Local Coordinates. These are centered upon you, the observer. Astronomy 30, Observing #3 Name: Lab Partners: Date: Materials: This lab, with the star chart completed from the pre-lab. Some sheets of paper for sketches. A pencil with eraser. A small flashlight, ideally

More information

Cartesian Coordinates Need two dimensional system 2 number lines perpendicular to each other X-axis is horizontal Y-axis is vertical Position relative

Cartesian Coordinates Need two dimensional system 2 number lines perpendicular to each other X-axis is horizontal Y-axis is vertical Position relative General Physical Science Chapter 15 Place and Time Space and Time Einstein Space and time related Single entity Time is the 4 th dimension! Cartesian Coordinates Need some system to tell us where something

More information

Satellite Communications

Satellite Communications Satellite Communications Lecture (3) Chapter 2.1 1 Gravitational Force Newton s 2nd Law: r r F = m a Newton s Law Of Universal Gravitation (assuming point masses or spheres): Putting these together: r

More information

Yr1 Lesson 1. The Great Circles of Astrology, the Angles, Precession,

Yr1 Lesson 1. The Great Circles of Astrology, the Angles, Precession, Yr1 Lesson 1 The Great Circles of Astrology, the Angles, Precession, Cosmic Intelligence Agency 2015 Astro Lesson 1! Signs, Symbols, Glyphs and Charts! The Celestial Sphere Great Circles of Astrology -

More information

Physics Lab #4:! Starry Night Student Exercises I!

Physics Lab #4:! Starry Night Student Exercises I! Physics 10293 Lab #4: Starry Night Student Exercises I Introduction For today s lab, we are going to let the Starry Night software do much of the work for us. We re going to walk through some of the sample

More information

Astronomy 103: First Exam

Astronomy 103: First Exam Name: Astronomy 103: First Exam Stephen Lepp September 21, 2010 Each question is worth 2 points. Write your name on this exam and on the scantron. Short Answer Mercury What is the closest Planet to the

More information

Chapter 2 Discovering the Universe for Yourself

Chapter 2 Discovering the Universe for Yourself Chapter 2 Discovering the Universe for Yourself 2.1 Patterns in the Night Sky Our goals for learning: What does the universe look like from Earth? Why do stars rise and set? Why do the constellations we

More information

Astrology Class Madison, Wisconsin. 43 North 89 West. September Daylight

Astrology Class Madison, Wisconsin. 43 North 89 West. September Daylight Astrology Class Madison, Wisconsin 43 North 89 West 7 32 September 21 2005 Daylight Astrology Class Madison, Wisconsin September 21,2005 7:32 43 North 89 West Names & Planetary Character Luminaries Symbols

More information

A Practical Guide to Observational Astronomy. M. Shane Burns

A Practical Guide to Observational Astronomy. M. Shane Burns A Practical Guide to Observational Astronomy M. Shane Burns September 15, 2017 Contents 1 Astronomical Coordinates and Time 1 1.1 Horizon Coordinates....................... 2 1.1.1 Diurnal and Annual Motions..............

More information

Chapter 2 Lecture. The Cosmic Perspective Seventh Edition. Discovering the Universe for Yourself

Chapter 2 Lecture. The Cosmic Perspective Seventh Edition. Discovering the Universe for Yourself Chapter 2 Lecture The Cosmic Perspective Seventh Edition Discovering the Universe for Yourself Discovering the Universe for Yourself 2.1 Patterns in the Night Sky Our goals for learning: What does the

More information

Aileen A. O Donoghue Priest Associate Professor of Physics

Aileen A. O Donoghue Priest Associate Professor of Physics SOAR: The Sky in Motion Life on the Tilted Teacup Ride Celestial Coordinates and the Day Aileen A. O Donoghue Priest Associate Professor of Physics Reference Points Poles Equator Prime Meridian Greenwich,

More information

Astronomy 122 Section 1 TR Outline. The Earth is Rotating. Question Digital Computer Laboratory

Astronomy 122 Section 1 TR Outline. The Earth is Rotating. Question Digital Computer Laboratory Astronomy 122 Section 1 TR 1300-1350 Outline 1320 Digital Computer Laboratory Leslie Looney Phone: 244-3615 Email: lwlw@wuiucw. wedu Office: Astro Building #218 Office Hours: T 10:30-11:30 a.m. or by appointment

More information

Astronomy 102: Stars and Galaxies Examination 1 February 3, 2003

Astronomy 102: Stars and Galaxies Examination 1 February 3, 2003 Name: Astronomy 102: Stars and Galaxies Examination 1 February 3, 2003 Do not open the test until instructed to begin. Instructions: Write your answers in the space provided. If you need additional space,

More information

The Earth is a Rotating Sphere

The Earth is a Rotating Sphere The Earth is a Rotating Sphere The Shape of the Earth Earth s Rotation ( and relative movement of the Sun and Moon) The Geographic Grid Map Projections Global Time The Earth s Revolution around the Sun

More information

Time, coordinates and how the Sun and Moon move in the sky

Time, coordinates and how the Sun and Moon move in the sky Time, coordinates and how the Sun and Moon move in the sky Using the colors and magnitudes of quasars drawn from the SDSS Catalog Archive Server to distinguish quasars from stars using the light they emit

More information

Chapter 2 Discovering the Universe for Yourself

Chapter 2 Discovering the Universe for Yourself Chapter 2 Discovering the Universe for Yourself 2.1 Patterns in the Night Sky Our goals for learning: What does the universe look like from Earth? Why do stars rise and set? Why do the constellations we

More information

Chapter 2 Discovering the Universe for Yourself. What does the universe look like from Earth? Constellations. 2.1 Patterns in the Night Sky

Chapter 2 Discovering the Universe for Yourself. What does the universe look like from Earth? Constellations. 2.1 Patterns in the Night Sky Chapter 2 Discovering the Universe for Yourself 2.1 Patterns in the Night Sky Our goals for learning: What does the universe look like from Earth? Why do stars rise and set? Why do the constellations we

More information

Questions for Today s Class?

Questions for Today s Class? PHYS 1403 Stars and Galaxies Questions for Today s Class? 1. Angles are important in Astronomy, What do I need to know about Angles? 2. What is a Celestial Sphere? 3. How do I Find Objects with my Telescope?

More information

Coordinates on the Sphere

Coordinates on the Sphere Survey Observations Coordinates on the Sphere Any position on the surface of a sphere (such as the Earth or the night sky) can be expressed in terms of the angular coordinates latitude and longitude Latitude

More information

2. Knowing the Heavens

2. Knowing the Heavens 2. Knowing the Heavens Ancient naked-eye astronomy Eighty-eight constellations The sky s ever-changing appearance The celestial sphere Celestial coordinates Seasons: Earth s axial tilt Precession of Earth

More information

Motions of the Earth

Motions of the Earth Motions of the Earth Our goals for learning: What are the main motions of the Earth in space? How do we see these motions on the ground? How does it affect our lives? How does the orientation of Earth's

More information

lightyears observable universe astronomical unit po- laris perihelion Milky Way

lightyears observable universe astronomical unit po- laris perihelion Milky Way 1 Chapter 1 Astronomical distances are so large we typically measure distances in lightyears: the distance light can travel in one year, or 9.46 10 12 km or 9, 600, 000, 000, 000 km. Looking into the sky

More information

Astronomy 101: 9/18/2008

Astronomy 101: 9/18/2008 Astronomy 101: 9/18/2008 Announcements Pick up a golf ball at the front of the class or get one from Alex; you will need it for an in-class activity today. You will also need the question sheet from Alex.

More information

Astrodynamics (AERO0024)

Astrodynamics (AERO0024) Astrodynamics (AERO0024) 3. The Orbit in Space Gaëtan Kerschen Space Structures & Systems Lab (S3L) Motivation: Space We need means of describing orbits in three-dimensional space. Example: Earth s oblateness

More information

In all cases assume the observer is located at the latitude of Charlottesville (38 degrees north).

In all cases assume the observer is located at the latitude of Charlottesville (38 degrees north). 1. Recalling that azimuth is measured around the sky from North (North is 0 degrees, East is 90 degrees, South is 180 degrees, and West is 270 degrees) estimate (do not calculate precisely) the azimuth

More information

1-2. What is the name given to the path of the Sun as seen from Earth? a.) Equinox b.) Celestial equator c.) Solstice d.) Ecliptic

1-2. What is the name given to the path of the Sun as seen from Earth? a.) Equinox b.) Celestial equator c.) Solstice d.) Ecliptic Chapter 1 1-1. How long does it take the Earth to orbit the Sun? a.) one sidereal day b.) one month c.) one year d.) one hour 1-2. What is the name given to the path of the Sun as seen from Earth? a.)

More information

Numerical Model for the Orbit of the Earth

Numerical Model for the Orbit of the Earth Universal Journal of Geoscience 5(2): 33-39, 2017 DOI: 10.13189/ujg.2017.050203 http://www.hrpub.org Numerical Model for the Orbit of the Earth S. Karna 1,*, A. K. Mallik 2 1 Physics Department, Tri-Chandra

More information

Lecture 4: August 30, 2010

Lecture 4: August 30, 2010 Lecture 4: August 30, 2010 How many hospitals are there in the USA? Announcements: First homework has been posted Due Friday (10 th ) First Observatory Opportunity Thursday Night September 2, 8:30pm Will

More information

The position of the Sun on the celestial sphere at the solstices and the equinoxes.

The position of the Sun on the celestial sphere at the solstices and the equinoxes. 1 2 3 4 5 6 7 8 9 10 11 12 13 EARTH IN SPACE Tillery, Chapter 18 Artist's concept of the solar system. Shown are the orbits of the planets, Earth being the third planet from the Sun, and the other planets

More information